On behalf of compassionate people everywhere, we implore you to help end the needless suffering of these animals by adopting strict and meaningful animal welfare policies worldwide, including the commitment to prohibit the purchase of eggs produced by hens who spend their miserable lives crammed into tiny wire cages.

The appeal comes after hidden-camera video, shot at Sparboe facilities in three states revealed hens crammed in tiny wire cages, dead hens left to rot in cages with birds still laying eggs for McDonald's Egg McMuffins, and workers burning off the beaks of baby birds without painkillers. Watch the undercover video here:

The investigation - which broke on ABC's Good Morning America and 20/20 - prompted McDonald's to cut ties with the factory farm. However, the company has failed to implement any meaningful animal welfare policies to actually address the main issue of concern: the inherently cruel practice of confining hens in tiny wire cages for their entire lives.

The letter points out:

While McDonald's has already established a 100% cage-free purchasing policy in Europe, your U.S. restaurants continue to support egg factory farms that confine hens for most of their lives in cages so small they can't even spread their wings. These poor birds never get to walk, run, perch, roost, dustbathe, build nests, see the sun, breathe fresh air, or do nearly anything that comes naturally to them. Common sense tells us that animals with legs and wings should be given the basic freedom to move.

Sadly, there is not a single federal law to protect hens from cruelty from the time they hatch to the time they are killed. While McDonald's brags about the "billions and billions served," millions of hens exploited for your restaurants are being grossly underserved. In fact, these animals are being abused in ways that could land your egg suppliers in jail, if dogs or cats were the victims.

The letter concludes:

It's a good time for some great changes at McDonald's. As the largest egg buyer in the entire country, McDonald's has the power -- and the moral responsibility -- to ensure that the eggs in its Egg McMuffins don't come from rotten egg suppliers.

Instead of merely sidestepping the issue of egregious abuse at one of its primary Egg McMuffin suppliers and switching to another egg supplier with equally cruel practices, McDonald's needs to require all of its suppliers to uncage hens and finally give these animals the modest freedom to spread their wings, walk, and engage in basic natural behaviors.

Let McDonald's know that these compassionate celebrities aren't alone in condemning its cruel practices. Please click here to urge McDonald's to end its use of eggs from hens confined in battery cages.

While McDonald's has the moral obligation and purchasing power to lessen the cruelty suffered by the millions of hens who are abused and exploited to produce eggs for its restaurants, consumers also hold enormous power of their own in preventing animal abuse by adopting a compassionate vegan diet.